Threading die



Nov. 16 1926.

C. F. COX

' THREADING DIE Filed Dec.

Patented Nov. 16, 1926.

UNITED stares earEN'r osFlcE.

CHARLES F. CIOIFLOIE BBIDGETGN, NE'W JERSEY, ASSIG-NOR TO THE COX AND SONS COM- PANY, OF BRIDGETON, NEW JERSEY, A COREORATION OF NEW JERSEY.

THREADIfNGr' DIE.

Application filed December is, 1925. Serial Nb. 76,262.

This inventionrelates to threading dies having tangentially arranged chasers and re lates particularly to dies of the type set forth in in 1 copending application for threading dies, Serial No. 29,437, filed May 11, 1925.

The principal object of the present invention is to provide in a threading die of the character referred to; an improved construction and mounting for the chaser holding clamp, whereby the clamp is more readily enabled to adjust itself to the position of the chaser and is thus capable of more firmly holding the chaser. 7

Further objects of the invention will be apparent from the following specification and claims.

In the accompanying drawing I have shown the embodiment of the invention which I now deem preferable, but it will be understood that the drawingis for illustrative purposes only and that changes may be made within the scope of the claims without departing from the spirit of the invention.

Of the drawings:

Fig. 1 is a plan view of the chaser, chaser holder and clamping means embodying the invention. V

Fig. 2 is an end view.

Fig. 3 is a perspective view of the chaser.

Figsat and 5 are views similar to Fig. 1 but showing other embodiments of the invention.

Referring to the drawings, 1 represents a chaser of the tangential'type having longi- 'tudinal thread cutting teeth 2 on the face thereof. The chaser is also provided with a longitudinal bearing surface 3 which is pref lstrip extendlng substantlally the full width erab'ly located along one edge and which is beveled or inclined with respect to the front face and also with respect to the back surface 4. Located in opposed relation to the beveled surface 3 is a clamping surface 5 which also extends longitudinally of the chaser. This clamping surface is immedi- 'at-ely adjacent the back surface 4. The

chaser is also preferabl provided with a longitudinal groove 6 in 1ts top which is immediately adjacent the clamping surface. 5

and which is provided with a wall 7 imme diately adjacent and at an angle to the said clamping surface 5. p

The chaser holder is represented at 8 and this can be of any usual or preferred type.

Ordinarily this chaser holder will be so coni the beveled bearing surface 3 thereof, in-

structed that it can be movably mounted in a suitable die body and moved inward or outward toadjust the die for different diam-.

eters of work. The chaser holder 8 is provided with a bearing surface 9 which is adapted to engage the beveled surface 3 'of the chaser and is also provided with a bearing surface 10 which is adapted to engage the back surfaces of the chaser.

The clamp for holding the chaser inplace on the body is shown at 11.. This clamp is provided with holes 12 adapted to receive screws 13. The holes are preferably countersunk at 12 to receive the heads of the screws 13. Vashers 14 are preferably provided under the heads of the screws. The screws are threaded into the body 8 and serve to force.

I and the clamp 11 adjacent the outer edge of the latter is a relatively movable strut 17.

Preferably this strut is inclined outward from the holder to the clamp and when so inclined it cooperates withthe screws 13 to draw the clamp and the chasers outward, thus firmly holding the back surface. 4 of the chaseragainst the surface 10 of the holder.

Preferably the strut is in the form of a of the chaser holder and clamp and the ends of the strut (the edges of the strip) are rounded as shown. The chaser holder has a transversely rounded groove 18 substantially parallel with the chaser and the chaser seat and spaced outward from the said chaser. The clamp 11 also has a transversely rounded groove 19 substantially parallel with the groove 18 and spaced further from the chaser, The strut 17 has its ends seated in these grooves as shown, and the curvatures of the surfaces of the grooves and of the ends of the strut permit the strut to freely swing to force the'clamp and chaser outward v as already mentioned.

The clamping'surface 5 of the chaser and stead of being parallel preferably converge toward the rear end of the chaser, that is, they converge from the front cutting end of the chaser to the opposite end thereof. Ordinarily and preferably the beveled surface 3 is parallel to the cutting teeth 2 and the clamping surface 5 is inclined with respect to the cutting teeth. The clamping surface of the clamp is inclined to conform to the inclination of the bearing surface As the result of the inclination of the bcforementioned surfaces, the clamp is enabled to hold the chaser more securely than it otherwise could. It will be obvious that any rearward longitudinal movement of the chaser could occur only by actually raising the clamp up bodily against the tension of the screws 13.

In addition to the inclination of the clamping surface as described, I also prefer to transversely incline the groove 6 so that the wall 7 thereof converges rearwardly towards the back surface of the chaser from the front end thereof to the rear end thereof. ihe hook port-ion 16 of the clamp is similarly inclined. As the result of this construction it will be apparent that the clamp is still further aided in holding the chaser against rearward longitudinal movement. It will be obvious that even if the surfaces 5 and 15 were not inclined, any rearward movement of the chaser could occur only by forcing the clamp toward the right as viewed in Fig. 1 and forcing it upward in a curved path determined by the strut 17. Obviously no such movement of the clamp could occur without actually breaking or elongating the screws 13.

"th the inclination of both the clamp-- ing surface 5 and the groove wall 7, a combined action is attained which makes it prac tically impossible for any rearward movement of the chaser to occur. It will be clear that any rearward movement of the chaser with respect to the holder and the clamp could occur only by forcing the clamp upward and laterally against the resistance offered by the screws 13 and the strut 17.

With my construction therefor, I make use not only of the frictional engagement between the several surfaces, but I make it mechanically impossible for the chaser to move without actually. moving the clamp away from the holder.

In order to further assist in preventing any rearward movement of the chaser, the clamping surface 5 is preferably serrated or knurled in a transverse direction. The chaser is necessarily hard and these serrations will either bite into the surface of the clamp or will mesh with similar serrations which may be formed on the surface of the clamp.

Fig. l shows an alternate form of the invention wherein the top'of the chaser and the wall 7, and the clamp '11 is provided with ,a hook portion 16 similar to the hook portion 16 and adapted to engage the all 7 The construction is otherwise sinilar and repetition of the description is rumeceF- sary.

In Fig. 5 I have shown another alternate form of the invention, wherein a clamping surface 5* is provided considerably below the top edge of the chaser. Adjacent the surface 5" is a wall 7". The clamp 11 is or may be exactly the same as the clamp shown in Figs. 1 and 2, and the holder 8" is modified to conform to the lower positions of the clamping surface 5 and of the clamp.

I claim: 7

1. In a threading die, the combination of a chaser provided with longitudinal thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an i opposed longitudinal clamping surface: a chaser holder having a beveled seat engaging the beveled bearing surface of the chaser; a clamp having a clampin surface adjacent its inner edge which engages the clamping surface of the chaser; means connected with the holder for forcing the clamp against the chaser; and a relatively movable strut interposed between the chaser holder and the clamp adjacent the outer edge of the latter, the said strut being inclined outward from the holder to the clamp whereby it cooperates with the said forcing means to draw the chaser against the holder.

2. In a threading die, the combination of a chaser provided with longitudinal thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an opposed longitudinal clamping surface and also having a wall adjacent and at an angle to the clamping surface; a chaser holder having abeveled seat engaging the beveled bearing surface of the chaser; a clamp having a clamping surface adjacent its inner edge which engages the clamping surface of the chaser and also having a hook portion which engages the aforesaid wall; means connected with the holder for forcing the clamp against the chaser; and a relatively movable strut interposed between the chaser holder and the clamp ad acent the outer edge of the latter, the said strut being inclined inc outward from the holder to the clamp wherer by it cooperates with the said forcing means to draw the chaser outward against the holder. r

3. In a threading die, the combinationof a chaser provided with longitudinal thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an;

opposed longitudinal clamping surface and also havin a wall adacent and at an an le to the clamping surface; a chaser holder having a beveled seat engaging the beveled hearing surface of the chaser; and having a transversely rounded groove substantially parallel with the said seat and spaced outward from the chaser; a-clainp having a clamping surface adjacent its inner edge which engages the clamping surface of the chaser and hav ing a hook portionwhich engages the aforesaid wall, the said clamp also having a transversely rounded groove substantially parallel with the said groove in the chaser holder and spaced further from the chaser; means connected with the holder for forcing the clamp against the chaser; and a strut having its ends rounded and seated in the respective grooves and with the said forcing means to draw the chaser outward against the holder.

4. In a threading die, the combination of a chaser provided with longitudinal thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an opposed longitudinal clamping surface and also having a wall adjacent and at an angle to the clamping surface; a chaser holder having a beveled seat engaging the beveled bearing surface of the chaser; a clamp hav ing a clamping surface adjacent its inner edge which engages the clamping surface of the chaser and also having a hook portion which engages the aforesaid wall, the clamp being provided with holes therein parallel with the face of the chaser screws of smaller diameter than the said holes and extending therethrough into the holder for forcing the clamp against the chaser; and a relatively movable strut interposed between the chaser holder and the clamp adjacent the outer edge of the latter, the said strut being inclined outward from the holder to the clamp whereby it cooperates with the said forcing means to draw the chaser outward against the holder. v

5. In a threading die, the combination of a chaser provided with longitudinal thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an opposed longitudinal clamping surface, the said bearing surface extending paral lelly with the cutting teeth and the clamping surface being inclined and converging rearward toward the bearing surface; a chaser holder having a beveled seat engaging the beveled bearing surface of the chaser; a clamp having a clamping surface adjacent its inner edge which engages the clamping. surface of the chaser and 1s simllarly in clined; means connected with the holder for forcing the clamp against the chaser; and a relatively movable strut interposed between the chaser holder and the clamp adjacent the outer edge of the latter, the said strut being inclined outward from the holder to 6. In a threading die, the combination of V a chaser provided with longitudinal thread cutting teeth on one face thereof and having a longitud nal beveled bearing surface and an opposed longitudinal clamping surface and also having a wall adjacent and at an angle to the clamping surface, the said bearing surface extending parallelly with the cutting teeth and the clamping surface being inclined and converging rearward toward the bearing surface; a chaser holder having a beveled seat engaging the beveled bearing surface of the chaser; a clamp having a clamping surface adjacent its inner edge which engages the clamping surface of the chaser and is similarly inclined and also having a hook portion which engages the aforesaid wall; means connected with the holder for forcing the clamp against the chaser; and a relatively movable strut interposed between the chaser holder and the clamp adjacent the outer edge of the latter, the said strut being inclined outward from the holder to the clam-p whereby it cooperates with the said forcing means to draw the chaser outward against the holder.

7. In a threading die, the combination of a chaser provided with longitudinal-thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an opposed longitudinal clamping surface and also having a wall adjacent and at an angle to the clamping surface, the said wall being inclined and converging rearward toward the back of the chaser; a chaser holder having a beveled seat engaging the beveled bearing surface of the chaser; a clamp having a clamping surface adjacent its inner edge which engages the clamping surface of the chaser and also having a hook portion which engages the afore- Zsaid' wall and is similarly inclined; means connected with the holder for forcing the clamp against the chaser; and a relatively movable strut interposed between the chaser holder and the clamp adjacent the outer edge of the latter, the said strut being inclined outward from the holder to the clamp whereby it cooperates with the said forcing means to draw the chaser outward against the holder.

8. In a threading die, the combination of a chaserprovided with longitudinal thread cutting teeth on one face thereof and having a longitudinal beveled bearing surface and an opposed longitudinal clamping surface and also having a wall adjacent and at an angle to the clamping surface, the said bearing surface extending parallelly with the cutting'teeth and the clamping surface being inclined and converging rearward toward the bearing surface, and the said wall being inclined and converging rearward toward the hack of the chaser; a chaser holder having a beveled seat engaging the beveled bearing surface of the chaser; a clamp; having a clamping surface adjacent its inner edge which engagesthe clamping surface of the chaser and is similarly inclined and also having a, hook portion which engages the aforesaid inclined wall and is similarly inclined; and also having a hookportion which engages the aforesaid wall; ineans CHARLES. r. ooX, 

